1. Field
An embodiment of the present invention relates to an electrode assembly and a secondary battery using the same.
2. Description of the Related Art
Recently, as portable electronic apparatuses have been miniaturized and lightened, research has been performed on a secondary battery as a driving power source. In particular, as portable wireless apparatus products including a cellular phone, a notebook computer, a personal digital assistant, etc. become lighter and more powerful, the importance of the battery used as driving power sources of the products is increasing.
Since the secondary battery can repeatedly be used through repetition of charging and discharging, the secondary battery is more economical than a primary battery. Further, the secondary battery has a high capacity and can be miniaturized and thus the secondary battery may have a high operating voltage and a high energy density per unit weight, the secondary battery is widely being used in high-tech electronic apparatuses.
However, a lithium secondary battery is rapidly growing in its applications because of its operating voltage of 3.7V, which is three times higher than a nickel-cadmium battery or a nickel-metal hydride battery that are now commonly used as a power source for portable electronic equipment, and because of its high energy density per unit weight.
In general, in regard to shape, there is high demand for a secondary battery such as a can-type battery or a pouch-type battery having a thin (or small) thickness which can be applied to devices such as the cellular phones and, in regard to materials, there is a high demand for a secondary battery such as a lithium polymer battery because of its advantages in energy density, discharge voltage, and stability (or safety).
As such, an electrode assembly housed in a can-type or pouch-type exterior case (or housing) includes an anode plate and a cathode plate and a structure (e.g., a separator) sequentially laminated or wound with the anode plate and the cathode plate and being interposed therebetween. In the laminate-type electrode assembly, electrode tabs extend from and are fused to the anode plate and the cathode plate and are electrically connected with anode and cathode electrode leads, respectively. In addition, a part of each of the electrode leads is exposed out of the can or pouch-type exterior case and electrically connected with a protection circuit module in a subsequent process.
However, since the electrode tabs may extend from the anode plate and the cathode plate in a line to be electrically connected with the electrode lead, the electrode tabs occupy a large space in the exterior case, thereby reducing the utilization of the inner space of the exterior case.